The present invention relates to the identification of the path and termination points of wires such as, for example, telephone lines through the use of natural events such as, for example, lightning strikes, and without use of network provisioning information.
The detection and geo-location of lightning, known as sferics detection, is currently of interest in a number of different areas. Three areas have lead to the development of reasonably priced, reliable and accurate detection and ranging equipment. These are aviation, electric power generation, and severe weather forecasting. The necessary technology has evolved to the point where a number of vendors can provide reliable off-the-shelf lightning detectors of high reliability and accuracy. These vendors include Insight Avionics of Buffalo, N.Y.; Boltek Corporation of Buffalo, N.Y., and Honeywell International, Inc., of Morristown, N.J.
Sferics technology enables the geo-location of lightning strikes through a number of different methods, including the following:
RANGE AND AZIMUTH FROM A SINGLE SITE—Some sferics detectors can produce useful information on the range and azimuth of a strike using phased antennas and pulse shape.
USE OF MULTIPLE SITES AND TIMING—Some systems use a series of highly time-correlated receivers to determine the passing of strike pulses. These systems are analogous to a bobber floating in water detecting ripples by bobbing up and down. A number of bobbers can detect a ripple pattern created when a stone is thrown into the water. The variation on the timing of the arrival of the ripples allows the calculation of the location of the thrown rock. This type of system is a global positioning system (GPS) or long range navigation (LORAN) system run in reverse.
Multiple site and timing systems are quite complex and costly. There is a need for atomic clock level of accuracy at the various locations. Even if GPS timing permits the establishment of add-hoc systems at much lower cost, there is still the need for exchanging information on wave form structure to correlate strike data. However, an advantage of these systems is their range and accuracy. Because of they have long range capability, a regional network is practical, facilitating the gathering information on short notice.
FLASH DETECTION—This is the most straight-forward form of detection. A light flash followed by sound is used to determine the range of the lightning strike. Optical detectors are used to determine the direction of the strike. The problems with this type of geo-location are obvious: limited range, sound detection complexity, complexity in the optical sighting.
DIRECT ORBITAL OBSERVATION—A series of satellites have been lofted to provide detection and tracking of lightning around the globe. Satellites such as the Microlab-1 and other orbital platforms such as the Space Shuttle have carried lightning detection payloads and have produced a wealth of information on strike locations. The occurrence of lightning, satellite location and system availability are the primary limiting factors for this type of data capture.
Existing sferics networks range from the very sophisticated timing-based networks run by national research and meteorological agencies to single-site systems run by private individuals. A large number (several hundred) of these networks makes information directly available on the Internet in a real-time or near real-time basis. The timing resolution ranges from one minute to the range of fifteen to thirty minutes.
Large sferics networks presently exist and are in operation. These sferics networks are used on a regular basis to determine the path and severity of weather information. For example, the United Kingdom's Meteorological Office operates the Arrival Time Difference (ATD) lightning location system. The ATD system is a very sophisticated system which uses multiple sferics detectors and rubidium clock based time coordination to achieve the range and accuracy cited. The ATD system incorporates a number of measurement improvement techniques to reduce false detections and to improve the geo-location capability of the system. A key element of the ATD system is use of a specific receiving station in the network of detectors as the “selector” station. By looking at the waveform recorded at the selector station and comparing this to the waveforms recorded by other stations, it is possible to match the strikes detected. As mentioned earlier, each of the strikes will produce a unique waveform. By matching the wave form patterns, it is then possible to correlate the measures of the various receivers. In addition, it is possible to discard false strike measurements by eliminating indications which were not seen by other sites.
Large national sferics networks such as the ATD system provide substantial continuous coverage over most of the highly populated portions of the world. A number of the national systems provide data in tabular form which can be used to identify specific strike location and timing.
Individual sferics systems often provide data in graphical rather than tabular format with a full screen representation of 50 to 100 miles. Even with fairly sophisticated “screen scraper” technology, the capability to isolate and identify specific strikes is somewhat limited. This problem is exacerbated by the imprecision of lack of a specific address for the detector. (For example, Diekirch, grand Duchy of Luxembourg is one given address. While the entire country is small, identifying the town of Diekirch can mean a location several kilometers on a side.) However, even with these problems, the graphical representations provide a strong reference set for activity estimation and detection probabilities.
In sum, the information stored by existing sferics systems generally provides location, severity and timing of strikes. The long term operational history of several of the detection networks has permitted the calibration and anomaly detection needed to get a high degree of accuracy over the operating field.
Presently the identification of the path and termination of a telephone line can present a tremendous challenge if the network provisioning information is lost or not available. The task of identifying the path can be done by a laborious examination of cable bundles and patch points, but this time and labor-intensive process is not practical over longer distances or in areas having a crowded or dense infrastructure. The time and effort needed to perform this process is often beyond the available resources and capabilities. In addition, the tracing of wire paths often requires the use of two teams (or sets of equipment), one at each end of the wire, i.e., line. The remote-end team must then move down the line. Travel and mobility requirements present logistics, timing and cost challenges, making it difficult if not practically impossible to trace a line. Moreover, the effort to track a specific line must in many cases be duplicated a number of times before a substantial knowledge base is recreated to derive any economies of scale in the tracing of areas' lines. Accordingly, there is a need for an accurate and efficient means of locating wire landlines, and applicants provide a technique based on sferics information that satisfies this need.